Field of the Invention
The invention concerns: an angiographic examination method to implement a rotational angiography using at least one x-ray radiator and at least one x-ray image detector, which are attached to the ends of at least one C-arm, a patient support table with a table plate to support a patient with the examination subject, a system control unit, an image system, and a monitor.
Description of the Prior Art
In 3-D imaging with C-arm systems (known as rotational angiography), for example as described by Patrick Kurp in “AXIOM Artis FD Systems/DynaCT—A Breakthrough in Interventional 3D Imaging”, Reprint from Medical Solutions, January 2005, pages 46-51, it is important that the examination subject (for example an organ or the head) to be imaged is supported centrally in the isocenter of the angiography apparatus. This central positioning is essential in order to be able to image the entire organ without truncation effects, and in order to achieve an optimal image quality.
In modern methods, it is up to the medical technician to manually implement this centering under x-ray radioscopy, for example as is described on pages 33 and the following in “AXIOM Artis—Quick Guide for Special Examinations—Software Version VB30 and higher” by Siemens AG, Medical Solutions, AX, 2006.
For example, an angiography system to implement such rotation angiographies is known from U.S. Pat. No. 7,500,784 B2, which is explained in the following in connection with FIG. 1.
FIG. 1 shows a biplanar x-ray system (shown as an example) with two C-arms 2 and 2′, each held by a stand 1 and 1′ in the form of a six-axis industrial or articulated arm robot. At the ends the C-arms 2 and 2′ are respectively mounted an x-ray source (for example x-ray radiators 3 and 3′ with x-ray tubes and collimators) and x-ray image detectors 4 and 4′ as an image acquisition unit. The first stand 1 is mounted to the floor 5, while the second stand 1′ can be attached to the ceiling 6.
The C-arms 2 and 2′ can be arbitrarily adjusted in space by the articulated arm robot (known from U.S. Pat. No. 7,500,784 B2, for example)—which preferably has six rotation axes and therefore six degrees of freedom. For example, they are rotated around their rotation centers situated between the x-ray receivers 3 and 3′ and the x-ray image detectors 4 and 4′. The angiographic x-ray system 1 through 4 according to the invention is in particular rotatable around rotation centers and rotation axes in the C-arm plane of the x-ray image detectors 4 and 4′, preferably around rotation axes intersecting the respective middle point of the x-ray image detectors 4 and 4′.
The known articulated arm robot has a base frame that, for example, is permanently mounted on the floor 5 or on the ceiling 6. A carousel is attached to this so as to be rotatable around a first rotation axis. A robot rocker is mounted on the carousel so as to be pivotable around a second rotation axis, on which robot rocker a robot arm is attached so as to be rotatable around a third rotation axis. At the end of the robot arm, a robot hand is attached so as to be rotatable around a fourth rotation axis. The robot hand has an attachment element for the C-arm 2 or 2′, which is pivotable around a fifth rotation axis and is rotatable around a six rotation axis orthogonal to the fifth rotation axis.
A table plate 7 of a patient bearing table 8 to accommodate a patient to be examined as an examination subject is located in the beam path of the x-ray radiators 3 and 3′. The patient support table 8 is provided with a control panel 9. Connected to the x-ray diagnostic device is a system control unit 10 with an image system 11 that receives and processes the image signals of the x-ray image detectors 4 and 4′ (operating elements are not shown, for example). The x-ray images can then be viewed on displays of a monitor screen mounted by a ceiling-mounted, longitudinally movable carrier system 12. Furthermore, a device 14, whose function will be described in further detail below, is provided in the system control unit 7.
The realization of the x-ray diagnostic device (shown in FIG. 1, for example) is not dependent on the six-axis industrial or articular arm robot with the stands 1 and 1′. In the angiography x-ray system typical C-arm apparatuses with normal ceiling-mounted or floor-mounted retention for the C-arms 2 and 2′ can also be used.
Instead of the C-arms 2 and 2′ that are shown, for example, the angiographic x-ray system can also have separate ceiling-mounted and/or floor-mounted retentions for the x-ray radiators 3 and 3′ and the x-ray image detectors 4 and 4′, which are rigidly coupled electronically with one another, for example.
The x-ray image detectors 4 and 4′ can be rectangular or quadratic flat semiconductor detectors that are preferably created from amorphous silicon (a-Si). However, integrating (and possibly counting) CMOS detectors can also be used.